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  1. #14
    Join Date
    Mar 2008
    Long Beach, CA
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    Quote Originally Posted by firefly View Post
    We have had a Rinnai tankless for 2 years now..I would not go back to a tank. You have digital temp control which is nice and unlimited supply. Mine is 188k BTU and I am on Geo so my desuperheater will be hooked up soon providing free hot water to preheat the tankless. Just keep in mind nobody points out the fact that the life expectancy can be at least twice that of a tank depending on your water quality maybe more since there is no tank to fail. Also the cost of power vent gas tank heater is not that much cheaper than a decent tankless. My last house had 50 gallon natural gas. My summertime gas cost three years ago( no furnace just hot water) was higher than my use now on tankless with two kids since that time(alot more usage). One other myth is the multiple use tale that you run out if you use more than a shower. Completely untrue. Mine will fire 8.5 gpm and easily handle two showers and a dishwasher at the same time. I hear from friends how they run out of hot before the garden tub is full or it just makes it and no hot left. No problem with these. Just do your research and look at YOUR needs, no one elses... Bottom line fact.... The tankless will save you money in the long run and they offer alot of convenience as well. Every thing negative that I ever read on these posts seems to come from people that have never owned one.
    A tank type water heater lasts 10 15 years. I truly doubt a tankless will last twice that long, especially since they have not been around long enough to validate those claims. Ive heard they last far less than tank types.

    As AACHP said, two showers and a dishwasher is not a major draw.

    When contractors and consumers complain about flow rate, it is not a myth.

    My 'bottom line fact' is that you will never recoup the thousands invested from your natural gas bill.

    Im glad you are happy with your tankless, but there are mixed feelings from within the industry as to their actual efficiency and comparable functionality. If you havent heard negative views of tankless units from professionals, you have probably done selective research. This thread consists of strictly contractors, unlike here, who shed a different light on them.

  2. #15
    Join Date
    Nov 2004
    SW FL
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    Hmm Spoil yourself with complexity

    Quote Originally Posted by Brian GC View Post
    A tank type water heater lasts 10 15 years. I truly doubt a tankless will last twice that long, especially since they have not been around long enough to validate those claims. Ive heard they last far less than tank types.

    As AACHP said, two showers and a dishwasher is not a major draw.

    When contractors and consumers complain about flow rate, it is not a myth.
    If one wishes to have the Best of all worlds,
    use equipment in series (with or without a circulating pump)
    as an integrated ( but complex and high $,$$$) solution.

    Use a high efficiency (92% - 95%) Hot Water Tank set at ~90' F
    1. which limits losses due to lower storage temperature and higher R-value of tank.
    and 2. HWT expands usable capacity

    and 3. Heat Pump (or solar) as heat source to increase efficiency

    and 4. Instant Tankless
    which provides ~ 30'F boost ( 120- -90'F) On Demand

    No one said high efficiency
    ________and convenience
    ++++++++ back-up
    .................. would be cheap

    nor provides a Reasonable pay-back
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

  3. #16
    Join Date
    Mar 2008
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    To answer your questions, here is my take as someone who uses one, not an installer or contractor.

    1. 80K BTU would be small..look bigger

    2.It is up to who you ask whether they are worth it. It seems that most of the time the people that use them like them ,and the people that install but don't own and use them aren't sure.

    3. You will absolutely not run out of hot water! You can't....

    4. Cost..Mine was only a few hundred more than traditional power vent gas not thousands as seen earlier

    5. You do not need a circulation loop unless you want one. I've got a 2400ft ranch with no loop.To me a loop defeats the purpose and savings go away IMO. There is a slight delay compared to tank but not bad. Next door neighbor has loop, to each his own.

    6. You will save money because they are more efficient. How much you save will be up to your lifestyle.

    7. Water conditions do not affect tankless unlike tank unless very high lime or something. On soft water I flush once a sediment at all. Think about it ....water and sediment sitting in the bottom of your heater for a few years vs. an hour or two until water flows through again.

    I have geothermal so my dusuperheater will soon preheat my tankless beating a tanked heater hands down . I saw you have boiler/oil heat or something?? Don't know what your setup is but there may be a way to use your system as a preheat or something. It is worth checking out your options before making a decision.

    I think you would be happy with one as long as it is sized right and good quality.Good luck

  4. #17
    Join Date
    Feb 2003
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    if you have a ranch with baths & kitchen far apart, consider 2 HWH to decrease pipe losses.
    if you have, or will have, teen-agers, use a tank type.
    -- I had 3, they learned to share 1 bath & use the 40gal left after my shower from a 50gal heater -- salesman stated my needed replacement needed to be at least 70gal -- no, the girls would have stayed in shower until 100gal 'ran out' !!
    harvest rainwater,make SHADE,R75/50/30= roof/wall/floor, use HVAC mastic,caulk all wall seams!

  5. #18
    Join Date
    Nov 2007
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    I would suggest installing an electric stainless steel hot water tank that in all likelihood would last as long as the building and may NEVER have to be replaced. We installed an OSO stainless steel hot water tank. What makes these tanks unique is that they heat and store the hot water at 175F. When you turn on a hot water tap anywhere in the house, this 175F water is mixed internally with cold water to give you a nominal output of hot water at 120F.

    This storage temperature with cold water mixing achieves 2 important things. First, the high storage temperature greatly reduces the risk of growing pathogens in your tank, such as legionnaires disease, which may be inhaled as an aerosol when showering. The 2nd accomplishment is that due to the higher storage temperature and the cold water internal mixing valve, the 65-gallon (Imp.) tank now has the equivalent hot water of a 90-gallon (Imp.) tank (108 Gal. U.S.) - without taking up any additional space.

    We have NEVER run out of hot water.

    Another factor to consider regarding a hot water tank is that during heating season, any heat loss from the tank contributes to heating your home. Electric resistance heating, which is what a hot water tank is, is 100% efficient. The DHW tank is mainly a net negative, from an energy consumption point of view, during those times when were air-conditioning our homes.

    A well-insulated stainless steel DHW tank is very efficient at storing the energy transferred to the water and will last MANY times longer than a conventional tank. You also have much greater peace-of-mind when away on vacation that this tank will NOT rust out and burst.



  6. #19
    Join Date
    Jan 2008
    Ottawa, Canada
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    Thread Starter
    Thanks for the feedback guys, seems like a 50/50 split. I'm thinking when it comes down to it, maybe a regular old hot water tank is the option for me. Constant hot water is not a concern for me, gas savings is. I'm not heating the house hydronically, so maybe instantaneous is overkill, a neat toy, but overkill all the same. Sounds like it would take a while for the price difference to pay for itself in gas savings. I'll probably get a whole bunch of flack for this but... I can rent a hot water tank from the gas company for 10 bucks a month, no fuss no muss, that'll probably be the way I end up going. Plus I don't have to install it.

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